When comparing Scala vs LiveScript, the Slant community recommends Scala for most people. In the question“What are the best (productivity-enhancing, well-designed, and concise, rather than just popular or time-tested) programming languages?”Scala is ranked 14th while LiveScript is ranked 50th. The most important reason people chose Scala is:

Pros

Pro

Immutable values

The immutable values make it perfect for working with concurrency

Pro

Multiparadigm

Scala supports both Functional and Object Oriented styles of programming. Beginners can learn both paradigms without having to learn a new language, and experts can switch between the two according to what best suits their needs at the time.

Pro

Type inference

Scala offers type inference, which, while giving the same safety as Java's type system, allows programmers to focus on the code itself, rather than on updating type annotations.

Pro

Compiles to JVM bytecode

Aside from Java itself, Scala is by far the most popular of the many JVM languages. If you're developing for Android, or a similar JVM-only platform, or otherwise need out-of-the-box cross-platform compatibility, but the performance of a compiled language, Scala is the way to go.

Pro

Very good online courses

On coursera you can find great introduction to Scala by Martin Odersky.

Pro

Type inference leads to a simpler syntax

Pro

Pro

Designed for High-level functional code

LiveScript has terse syntax for common functional operations like map, and ships with a library, prelude.ls, with many of the functions most commonly used by functional programmers.

Pro

Good amount of programmer flexibility

There's a huge range of features that can make common tasks faster.

Pro

ECMA 6 Features

It is the declared goal of LiveScript’s creators to track ECMAScript 6. Hence, the language gives you ECMAScript 6 plus type annotations (which are optional).

LiveScript's module syntax is currently a bit behind the ECMAScript 6 specification (something that will be fixed eventually). It supports two module standards: CJS (Node.js) and AMD (RequireJS).

Pro

Fixes coffeescript scoping issues

= is used to declare variables in the current scope, in order to redeclare variables of outer scope := is used. This way bugs are reduced.

Pro

Supported by WebStorm and Visual Studio

Cons

Con

Can be intimidating for beginners

Scala is an industrial language. It brings functional programming to the JVM, but not with a "start small and grow the language" perspective, but rather a very powerful language for professional programmers.

Con

Static type system inherits cruft from Java

The type system is too complicated yet still less powerful than Haskell's.

Con

Way too complex for beginners

Even for seasoned programmers it's a difficult language.

Con

Strong functional lean

LiveScript is designed to be a high level functional language. For people who prefer a more imperative approach it can be hard to get used to.